<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <mate http-eauiv="X-UA-Compatible"content="IE=edge"></mate>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
     <script src="vue.js"></script>
</head>
<body>
    <div id="app">
        <div v-if="isShow" ref="self">
            test
    </div>
    <button @click="isShow=!isShow">更新</button>
    </div>
    <script>
        var vm = new Vue({
        el: '#app',
        data: {
        isShow:false
    },
    beforeUpdate(){
        console.log('更新之前')
        console.log(this.Srefs.self)
    },
        updated() {
        console.log('更新之后')
         console.log(this.$refs.self)
        }
    })
        </script>
</body>
</html>